Applications Of Derivatives Question 258
Question: On the interval (1,3), the function $ f(x)=3x+\frac{2}{x} $ is
[AMU 1999]
Options:
A) Strictly decreasing
B) Strictly increasing
C) Decreasing in (2, 3) only
D) Neither increasing nor decreasing
Show Answer
Answer:
Correct Answer: B
Solution:
$ f(x)=3x+\frac{2}{x} $
therefore $ {f}’(x)=3-\frac{2}{x^{2}} $
Clearly $ {f}’(x)>0 $ on the interval (1, 3) \ $ f(x) $ is strictly increasing.
BETA
